reynolds



Aug- 22, 1951 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS 15 Sheets-Shea?l 1 Filed June 16, 1958 S: A.O

)ITL s `.\i Il lll R. m O m N W y R E e O V R T m31 N T :555:25 I m Amuoro C wh W w e n s r cui@ my@ .m A s 2.6m 3&5 2355 om A nmson. M l mWS i z 2 f 2:30 vB20 D c222 E. v 2mm j 32.3 t uw Uv Op E @E c.: @I 29m2a:

Allg- 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS l5 Sheets-Sheet 2 Filed June 16, 1958 R. O||||||||l I. IIIIIIIIIIIIIIII T m Ill V i N lll .l I||| NN ONW m t Eoowzzow N 265m 222cm li Il I lll l III Il Q :c: 2.8m u.; Q::oo Il l oh 2S522 20E@ All l I. I. Il l l |||V||| H.|||||||I||||||||H||||||.II.I||HHH cuis U33 wcozuoccoo l lllllllllllllllIl Andrew Craig Reyno|ds,Jr.

TTORVEYS Aug- 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS 15 Sheets-Sheet 3 Filed June 16, 1958 :252mm:3.6 L

INVENTOR.

Andrew Craig Reynolds, Jr.

TTORNEYS ug. 22,11961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATNG APPARATUS 15 Sheets-Sheet 4 Filed June 16, 1958 ESE umINI/ENoR.

Andrew Craig Reynolds,Jr.

Enum 53cm ATTORNEYS l5 Sheets-Sheet 5 Aug. 22, 1961 A. c. REYNOLDS, JR

SIGNAL GENERATING APPARATUS Filed June 16, 1958 Aug. 22, 1961 A. c.REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS 15 Sheets-Sheet 6 Filed June 16, 1958 lug sTru. f. l, S

Aug- 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERTING APPARATUS 15 Sheets-Sheet 7 Filed June 16, 1958 Ewa 1,5Sheets-Sheet 8 A. C. REYNOLDS, JR

SIGNAL GENERATING APPARATUS Filed June 16, 1958 Aug. 22, 1961 AndrewCraig Reynolds,Jr.

ATTORNEYS Aug. 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERTING APPARATUS l5 Sheets-Sheetv 9 Filed June 16, 1958INI/ENTOR.

Andrew Craig Reynoldsr ATTORNEYS s .mi

AU8 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPMuuusr l5 Sheets-Sheet 10 Filed June 1.6,l 1958liTToRNEYS l IHM IMHTV Andrew Craig Reynolds,Jr.

Aug- 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS 15 Sheets-Sheet 11 Filed June 16, 1958 R N eO ER T Wm. T I m A 15 Sheets-Sheet 12 Aug. 22, 1961 A. c. REYNOLDS, JR

SIGNAL GENERATING APPARATUS Filed June 16, 1958 migo :252mm zgui curiw530m Oleo Aug. 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS Filed June 16, 1958 l5 Sheets-Sheet 13 GroupSelection Circuit Selection Funcan A B C D E F G H I J Off Start. l 2 s4 I4 le la 2022 24 262e 3032 34 56 354042 4446485052 51585960 Grou Cif'Break Cam Break Cam Make Cam P cult o. No, A B c D E F G H I J A B c o EOOO.. C |-2 ...DI C |-3 ...Il l l-4 DI... I |-5 DI... C

l I I I l l l l f i i I 'l i l' 3- I O O O O C 3-2 C O O C s-s e n n o oo 3-4 C l C C l C 3-5 C.. O .l C I l l l 'l E: E i i :l I

32| O .0000 32-2 O OO... 32-3 O .0.0 32-4 0 OOO.. 32-5 O .0.0

INVENTOR.

Andrew Craig Reynolds,Jr.

TTORNEYS Aus. 22, 1961 A. c. REYNOLDS, JR 2,997,702

SIGNAL GENERATING APPARATUS Filed June 16, 1958 15 Sheets-Sheet 14 FIG.3

T208 Plate Circuit WV Relay 210 2|0| c Code A'C- 202 Start Cam 2") RelayC ^2l3 Code Make 2038 Cam 205 FIGA 5 2|9 2 Off e 204 (2'9 L I Zig-ID? 0"Mzo M sniff o or Start Cam Moto' IO R.P.M.

5202 2262 v o 22| V Cycle 222 Cgntrol 224 am V C @f 225 Load Load supp|y223 Cam (203 INI/ENTOR.

Andrew Craig Reyn0|ds,Jr.

ATTORNEYS Filed June 16, 1958 AU8- 22, 1961 A. c. REYNOLDS, .1R2,997,702

SIGNAL GENERATING APPARATUS l5 Sheets-Sheet 15 I N V EN TOR.

Andrew Craig Reynolds,Jr.

ATTORNEYS United States Patent 2,997,702 SIGNAL GENERATING APPARATUS Y vAndrew Craig Reynolds, Jr., Waterbury, Conn., vassigner to General TimeCorporation, New York, N.Y a; corporation of Delaware u Filed June 16,1958, Ser. No. 742,333. 33 Claims. (Cl. Milf-309.1)

This invention relates to electrical signalling systems, u

and more particularly to a codepulse generator for the supply of pulsecoded signals to receiver relays which control the operation of loaddevices. The apparatus of the invention permits the establishment of 'aprogram of such` signalsto control the operation of a large number ofload devices in a desired s'equence over a substantial period of time ofthe order of hours or days. For example, the present invention providesa centralized control by means of which the lights, bells and theheating and Ventilating and other utility schedules in a large publicschool can be controlled according to a preestablished program, with oneschedule for certain claysv of the week and other schedules for otherdays of the. week. The program system of the invention also includesmeans whereby they pre-established program may be overridden by'manually inserted signals. f The signals are distributed over some formof transmission line, for example a single phase alternating currentlighting circuit to which all of the. load devices are connected throughsuitable signal detecting and discriminating devices so that the variousload devices respond to a selected. signal or signals and to no'others.

' In the accompanying drawings: y

FIGS. lato 1L (hereinafter sometimes referred to col.- lectively as FIG.l) are' a schematic diagram of one embodiment of the signal programmingand generating apparatus of the invention;

, FIG. lm is -a diagram showing the positional relationship to eachother of FIGS. la to 1L;

FIG. 2 is a. diagram illustrating the nature of the pulse code systememployed in the apparatus of FIG. 1;

FIG. 3 is a diagram of a binary dual coded'relay useable with theapparatus of FIG. l as a receiving device for controlling the operationof a load device in response to particular signals generated by theapparatus of FIG. 1 and selected by that relay;

FIG. 4 is a diagram of a latching motor relafy useable with the relay ofFIG. 3 for direct control of power applied to a load device; FIG.` 5 isa diagram illustrating a few of the pulse code combinations whichl makeup the various signals generated -by the apparatus of FIG. 1; and

- FIG. 6 is a perspective view of a .program instrument I suitable foruse in the apparatus of FIGQl.

The apparatus of FIG. 1 permits the generation of any one of a largenumber of diterent pulse code signals at any one of a succession ofconsecutive time intervals within a longer time interval, and providesfor the scheduling of such signals in advance and their automaticgeneration at the desired` times. Forexample, the short time intervalsmay be of one minute each, the apparatus scheduling a signal atvauyminute .or minutes ofA a twentyfour hour period. Certain ofv thesignals so scheduled may be' made effective, for actual generation andtransmission, in selected twelve hour (or other longer) periods, whileother combinations of the signals scheduled are arranged to betransmitted during other twelve hour periods. The total time cycle forthe apparatus may thus conveniently be made of seven days for example.

The signals generated may be understood. with reference to FIGS. 2 and5.

the nature of the coded pulse signals employed. All

signals occupy the same. signal time interval which may nature, aso-called function determining pulse identiied` in the figure by thelegend Ofi The code pulses A to4 I are of specified length and duration,and each, when. present, occupies a predetermined position in the signaltime interval, which is com pleted with the time allotted to the Ottpulse. Two signals differing only in the presence and absence of the. Oipulse actuate the same load devices, -but serve respectively to changetheir state of operation in opposite senses, for example from on to oir'and from off rto on,- so that a load device. may be turned oit by asignal includ-` ing an Off pulse and is turnedy on by a signal notinclud.- ing, an'Ot pulse.k

In a preferred embodiment of the invention to be described in detail,the coded pulses or pulse intervals A to J are distinguishable into twogroups. The total number may be of any value., ten being. shown in thesystem illustrated. These are divided into what may be called groupselection" pulses and circuit selection pulses. FIG. 2 shows the ten.code pulse. intervals equally divided between` group selection andcircuit selection pulses, but any other division may be adopted instead.

The characteristic feature of the group selection pulses is that the.absence of a` pulse, at the time of any one thereof, identities a signaldifferent from a signaly otherwise the same. but including a pulse atsuch time. By this is meant that a load device which, lby operation ofits associated signal detecting device, called a coded relay, wouldrespond to a signal not including that particular group selection pulsewill not respond to a signal otherwise the same but which does includethat particular group selection pulse. l The same load device,responsive via its coded relay to a signalincluding a. particularcombination of group selection pulses (and no others) and a particularcircuit selection pulse (and no others)v will, on the other handrespond,4 in the same way, to another signal which diiers only in thatit includes one or more additional circuit selection pulses. Y

The pulses generated by the apparatus of the invention are typicallypulses of A.-C. voltage at power line frequency, although they may ofcourse be of any other frequency including direct current, and theapparatus illustrated in FIG. l includes means whereby the pulses may-be generated in any one of a plurality of frequencies. For each suchcarrier frequency the pulse code of FIG. 2 provides a number ofdiscriminable signals (apartzthe distinction between on and oit signalsdetermined by the absence or presence of the Off pulse) given by thenumber 0f circuit selection pulse positions times two to the ex:- ponentgiven, by the number of group selection pulse positions. Thus with liveof each, the numberof dis,-

criminable signals for each carrier frequency is five times FIG. 2 is adiagram of voltage against time, and shows two tothe fifth power, or onehundred and sixty.

Before proceeding to a description of the invention itself,l anembodiment of which is illustrated in FIG. 1, it will. be informative todescribe the devices which are controlled by, and which discriminateamong, the various signals of the general form of FIG. 2. FIG. 3 is adiagram of one form of pulse detecting or discriminating device operableby means of the invention to energize, in response to the signals forwhich it is coded, either van, on conductor orl an ott conias/tensed`Aug. 22, 1.961,'

on or oi of a useful load device by iiieansl of the motor" driven relaydevice of FIG. 4.

FIG. 3 illustrates what ,may -be called abinary dual coded relay. Thisdevice lresponds' to'v coded pulse signalsof the type illustrated inFIG. 2 when of a selected carrier4k frequency. -It will provide anoutput signal by energization of one of' its output conductors' v204 and20'5," to signals of that carrier'frequency containing' a par` ticularcombination ofthe pulses' A to E (and no'other of those pulses A to E)and containing ia'particular vone ofthe pulses F to J (whether other of`the pulses F to' J are present orinot). f' The pulsed signals in 'theformo'f pulses fan audio' frequency arrive via th'e power vlinecmprisingvcondctors 202 and 203, the latterof which' may b'e grounded.Ypower line supplies power for 'actuation of th'e mechanism' of FIG. 3.It is to kbe understood that` afIl'nultiplicity of devices of the typeshown in FIG. 3 Aare"connected' to. the same power line 202-203. 'Thismultiplicity may include as many as one hundred and sixty, forA theeir-V ample described of tencode pulses divided into iive'group A thebeginning of the Oi pulse.

selection and ive'circuit selection pulses. 'jIndeed itniay include amultipleof onev hundred'and sixty, 'if' the pulse signals are applied tothe powerline in' plural carrier frequencies, the devices according toFIG. 3 of each such multiple responding only to pulse signals in aparticular carrier frequency.

To exclude pulsed signals `of other than-a single carrier frequency, theincoming pulses are passed -through 'a lte generally indicated at V206before being' applied tothe control grid of a gas controlled dischargetube '207, `of the type commonly known as a thyratron.'- This'` tube hasin its plate circuit the-coil of an electromagnetic relay 208. -Thestart pulse of every signalfof the frequency towhich iitler 206 is tunedwill energize relay 208 lClosing of its normally open contacts 208-' 3applies" power from conductor 202, via conductor 209,' via closedcontact 210-1'of a cam 210 andvia` conductor 211to vthe coil of a memoryrelay 212, whose circuit is completed to conductor 203 via conductor213y and c1o`sed' co1 1`ta`ct 214-1 of a cam 214. t Energization ofrelay 212 establishes for it af'holfding circuit at normally opencontact 212-2; By closing-of contact 212-1,` it`- also completes -acircuit between conductors 202 and 203 for -a motor 215. This motor, a'so-called shift motor, is a synchronous'motorwith an 'to which therelay of FIG.

,4 3 in question is to be responsive."Y In practice "thse" teeth areslightly narrower'iri their effective time duration than the code pulsesA to l. The code make cam 214 leaves its associated contact 214-1 closedduring the start pulse and possesses teeth phased only for thoseofthepulses A to E required to be absent in the code signal to which therelay of FIG. v3. including such code make cam is to be responsive. Thesignal duration cam 216 holds open its associated contact 216--1 at alltimes except the time of the signal duration or Off pulse at the endofthe signal cycle of FIG. 2, the .contact 216-1 being-permitted toclose just after The operation vof the relaytof FIG.I 3 may now becirplained.A As'sumezthe relay `is built to Vrespond'to the Signal A B CF; by whchnotation iS meant a Signal including pulses 'A B C and E andlnot including pulses Assuming application to conductors 202 and 203 ofpulses of the carrier 'frequency which can pass through filter 206, thestart pulse which is included in every pulse sequence wil l, as alreadydescribed, energize memoryy v relay 212, provide a. holdingcircuitthereforeand start motor 215. 'Since thevrelay is to respond Vtothecodel A B C D F, code vbreak cam 217 possesses teeth at the times ofpulses A,B C and F and the code lmake cam 214 possessesl teeth atY thetimes of pulses D and E. At

the endofthe start `,pulse tube'207 vgoes out and relay 208 returns. tode-energized condition. Motor 215 however is heldenergizred after; theend of the start pulse by closing of -contact 218-1 and relay 212 isheld energized by closing of contacts 217-1 jon cams 217 and 212-2 onrelay 2 12,I contact 214-1 -on, cam 214 remaining closed until time forpulse D. At the; times of each of the pulses A B and C, tube 207 resagain so that the circuit forrelay 212-though opened during each ofthose pulses atv contact 217-1by yteeth'on cam 217, is saved at con- Atact 20,8-3.- i

associated gear train giving an output shaftspeed of one The cams areshown in the figure in their reset position, which they occupy when themotor is de-energized. 1 Motor hold cam 218 controls normallyopencontact 218-11, the cam being so cut'and phased that thel contact isopenfrom' reset position of motor 215: inwhich it starts until a -tirneprior' to theend ofjthe 'start pulse. Thus all binary"4 coded relays'ofthetype-shown'in FIG. 3 tuned to the same carrier frequency will respondto the start pulse in each coded signal of that frequency appliedthereto tothe extent of effecting energization of their shift motors215, and these-shift motors; will operate for a full one minuteinterval-b'y completion of a circuit therefor at their' motor- -hold c'a'nls".The code start cam -210 is socut and-phased as to open its associatedcontact 210-1 just after ltheendl of the start pulse which initiatedrotation of that cam.

During each of the pulse periods D and E, contact 214-1 `is opened by atooth on cam 214, so that a signal including either of those pulseswould, by opening contact 208-4, result in loss of the circuit for relay212 between-conductors213 and 203.

Pulse F, by energizing the tube 207' and transferring relay 208, againsaves the circuit for the memory relay 2 12 despite opening of contact217-1 by a tooth on cam 217.v ',Relay 212 is therefore held energized tothe end of the minute code pulse cycle, a tooth on cam 217v openingthecontact a fraction of a second prior to the end of that minute toinsure an opencondition of the contact upon the arrival of the nextpossible start pulse. a In;v order to permitthe turning on or off of aplurality of separately discriminable` load devices at one and the sametime the code make cam 214 is not provided with teeth during any. of thepulse periods F through J. In consequence the lrelay of FIG. 3 willrespond to any signal conforming tothe description A B CD F,irvrespective of the presence or absence of any one or more of theApulses G H I J.v This is the physical foundation of the-distinctionbetween group selection and circuit selection pulses above discussed, aparticular sequence of Y Ate E pulses-seems A *Bfcvnn identify-ing and'Conj- The code break camV 217 is provided with a tooth as shownin thedrawing initially holding open the associated contact 217-1, but thistoothis -cut anlphased so that contact 217-1 closes just prior to theend-'of-the start pulse. The code break cam is provided with additionalteeth-phased forfthe time -pos'itionsof each of the pulses in; the'seesA 10J' :required te harp-resent i'xrth c'ofie trolling any one ormore'of a group of load devicesor circuit s,' according as the signalincludes from one to tive of the pulses 4F to J, in' addition to thesequence A B C D If a signal of :the form A B C DTE' F has been receivedby tube207, relay 212 will be held energized for the full minute andthere will despite opening of contact 210-1 be power on-conductor 211leading into contact 216-1 at the time of the Off pulse and this powerwill, by closing of lcam 216, be passed to the outgoingy conductor 205.0f .204. according es. the. atenei f1.9@ .or does 1,10-t includeapplication of the invention the actual load device is controlled fromthe binary dual coded relay of FIG. 3 through a latching motor relayschematically illustrated in FIG. 4. In FIG. 4 conductors 204 and 205 ofFIG. 3 lead to the contacts 219-1 and 219-2 of a switch 219 driven by acam 220 coupled to a shift motor 221. This motor is also of low speedhaving an output shaft speed for example of l r.p.rn. In addition to thecam 220 there are coupled to the motor 221 a cycle control cam 222 and aload supply cam 223. The load device itself is illustrated at 224.

Cam 222 has twice as many teeth as cams 220 and 223, and the three camsare coupled together at unity drive ratio. On each 'cam the teeth andthe notches between teeth have the same angular width.

For one revolution of the output shaft of motor 221 the cams 220 and 223shift their associated switches 219 and 225 from one to the other of thepositions shown therefor, whereas during such a revolution the cyclecontrol ca-m 222 rst closes and then reopens its associated switch 226.

Assume that on the last cycle of operation of shift motor 221 switch 219was left connected to contact 219-1 and conductor 204. This correspondsto an olf condition of the load, as indicated by the open condition ofswitch 225, switch 226 vbeing open also. The latching motor relay of theFIG. 4 will yaccordingly respond now to an on signal only. That is tosay, the signal pattern made up of pulses illustrated in FIG. 2 must notinclude an Off pulse. I-f it does not, the binary coded relay of FIG. 3will, upon receiving a proper signal such as that including the code A BC l F in the example just discussed, apply power at the end of theminute interval to conductor 204. This will energize the shift motor 221in FIG. 4. Before switch 219 in FIG. 4 is trans- `ferr'ed to thede-energized Oi conductor 205 the cycle control cam 222 will haveprovided motor 221 with a substitute energizing line directly atconductor 202 so that that motor can complete its cycle of operation,transferring vswitch 219 to the Off line 205 and closing the switch 225by means of the load supply cam 223. Shift motor 221 is then turned olfby the cycle control cam 222, opening the connection between conductor202 and the shift motor.

The result of application of the signal A B C F (with or without any ofthe pulses G H I and J) has thus been to apply power to the load device224 and to leave switch I219 connected to the Ol conductor 205. Thestate of operation of load device 224 can now be changed only 'byapplication to the binary relay of FIG. 3 of a signal, of appropriatecarrier frequency, including not only the start pulses but the codedpulses A B C F and an Ofi pulse.

lFIG. 5 illustrates the vmakeup of the code break and code make cams ofthe various binary coded relays of the type illustrated inl FIG. 3 whichcan be keyed byl 'rne'ansof code pulse signals of the general typeindicated lin FIG. 2. 'It thus indicates the nature of those signalsthemselves. The signals, and the corresponding cam patterns, are`adt'lantageously grouped by groups each of which includes all signalshaving the same patterns of group recognition pulses A -to E, i.e.pulses which must be present, with no extras, to permit perception inthe coded relays of the type illustrated in FIG. 3, of the tern-.po'rally succeeding circuit selection pulses F to J.

Since Ithere are, in the example under consideration, ve dilerentcircuit selection pulses, there are ve signals in :each group. The firstgroup is that including selection pulses A B C D E. The second group(not illustrated) includes group selection pulses A B C D The third,which is illustrated, includes group selection pulses A B C l5 E, and soon, to the thirty-second, which includes group selection pulses T5 Thepattern of teeth ou the code break and code-make cams 217 and 214 of theIbinary dual coded relays of the type shown in FIG. 3 is correspondinglyillustrated in FIG. 5, where a dot represents a tooth.

Referring now to FIGS. la to 1L, there will be given a detailed`description of a presently preferred embodiment of the invention. Thepulses which make up the coded signals which have been discussed are'generated in a transmitter or oscillator 1 shown in FIG. lL. Thistransmitter is a device, known per se, including a plurality of inputconductors 2, 4, 6 and 8 in the example illustrated, and a pair ofoutput conductors designated 10 and 203, the latter being the groundedpower conductor of FIG. 3. A large coupling capacitor r11 of lowimpedance at the audio carrier frequencies employed,

couples conductor 10 with the other conductor 202 of the power lineshown in FIG. 3.

Each of the input conductors 2, 4, 6 and 8 is arranged to supply to thetransmitter 1, upon generation thereof by the remaining apparatus ofFIGS. la-lL, pulses of 60 cycle voltage of any of the sequencesdescribed in connection with FIGS. 2-5. Such a sequence arriving overthe conductor 2 causes delivery by the transmitter to the power line202, 203' of a corresponding sequence of pulses of a first carrierfrequency f1 while the same sequence arriving over conductor 4 causesdelivery t'o conductors 202 and 203 of the same sequence of pulses, butin a carrier frequency f2, and so on. The number of output lines 2, 4, 6and 8 from the apparatus of the invention is of course a matter ofchoice, from one to any desired larger number.

The transmitter 1 contains an audio oscillator, a power amplifier, andswitching circuits to select the various frequencies in the audiooscillator. Since these are conventional elements, it is not believedthat their construction, or that of the transmitter 1, need beillustrated or described in further detail.

For development of the pulse sequences to be delivered to conductors 2,4, 6 and 8 at selected minute time intervals, the apparatus of FIG. lbegins with a master clock 12 shown in FIG. la. This master clock,together with the other components illustrated in FIG. la and lb abovethe dashed line Af-A in both of those gures, applies D.C. currentimpulses at one minute intervals between conductors 14 and 16 fordelivery, via the polarity relay assembly generally indicated at 18, toconductors 20 and 22 for energization of the driving solenoids 24 ofthree program instruments one of which is shown in the perspective Viewof FIG. 6. The elements of structure of these instruments essential foran understanding of the circuit of FIG. l are shown in that ligure,whereas FIG. 6 illustrates the actual construction of the programinstrument.

'I'he program instrument of FIG. -6, generally indicated at referencecharacter 26, is a device known per se. It includes a plurality ofschedule drums 28 driven together step by step at one minute intervalsby a timing armature 30, in response to timing pulses supplied by amaster clock to a solenoid 24 as shown in FIGS. la and lb. The drumsmake one revolution in steps, traversed in a time of two hours. Eachdrum has twelve side-by-side peripheral rows of equally spaced holesinto which scheduling pins 322 may be inserted, to bring themsuccessively under sensing fingers 34, of which one is provided for eachdrum. The sensing fingers are mounted together on a carriage, notvisible in FIG. 6, for axial movement with respect to the drums undercontrol of va. twohour helix 36 which serves to shift the lingers fromone row of pins or pin holes to the next at the com. pletion of eachrevolution by the drums. A switch 38 (FIGS. le and lf), not visible inFIG. 6, is provided for each drum, arranged to be closed by the sensingfinger of that drum when a scheduling pin passes under the sensinglinger.

By virtue of the twelve rows of scheduling pin holes with 120 holes ineach, each drum provides 1440 00n- 'present invention.

"17 Secutve pin holes, one 'for every minute in a twenty-four hourinterval. Each drum can therefore develop a signal at any one or moreminutes of a days time interval.

For optional connection in series with the switch 33 of eachdrum theprogram instrument of FIG. 6 includes a second switch 40. These switchesare spring loaded to open position, like the switches 38, and each isclosed for twelve hour periods by means of a calendar cam 42. Thesecams, one for each of the drums of the program instrument, are providedwith 14 teeth, and advance by one tooth interval at the beginning ofevery twelve hour period by operation of a calendar pawl 44. The teethcan be bent out of the way to leave the associated switches 40 openduring the twelve hour periods alloted to such teeth, thus renderinginelfective, if the switch 40 of the appurtenant drums are in circuit,the scheduling pins the corresponding twelve hour portion or portions. of the drum cycle. .Referring now to FIGS. le and 1f, the signalgenerator of FIG. 1 Iincludes three six-drum program instruments of thetype illustrated in FIG. 6. In these gures, only .the drums,.switchesand calendar cams are shown. 28T-A to 28F of one instrument areallocated one to each ofthe pulses or pulse times A to F of FIG. 2lf0n'a second instrument four drums 28-G to 28-1 are similarly allocated tothe pulse times G to l respectively, two drums 28-F and 28- areallocated to the selection of one of the four frequencies f1 to f4 inywhich `the coded pulse signals are ultimately to be generated by thetransmitter 1. On these two program instruments the switches 40 ofthecalendaring function are not used, the drums thereof beingemployed,.together with the drums 28-On and 21S-Off of the third programinstrument, to set up a pattern of signals'of the type illustrated inFIG. 2 available to cover a twenty-four hour interval. .v Inthc third.program instrument four drums I to IV are employed with their calendarswitches and cams 40 and 42 to permit selection, during twelve hourperiods ofthe week, of any one of four schedules, i.e. sequences f thesignals set up on drums 28-A to 28-l, 28-F' and ,28-Ff includingdifferent sub-combinations of those signals. f

The last two drums 28-On and 28-O1f of the third program instrument areemployed, without calendar cams and switches,` to schedule the On or Offnature of the signals scheduled on drums 28-A to 28-I, 28-F and 281-i.e.,the absence or presence, respectively of the O pulse of FIG. 2 inthe signals so scheduled. `The 60 cycle current pulses, at the times ofthe start, A-J and Ol pulses of FIG. 2, which are sent, via one of ythefrequency selecting relays 46v-f1 to 46-f4 of FIG. `r1L to conductors 2,4, 6 or 8 and thence into transmitter 1,l are ultimately generated in acycling device generally indicated at the dash line box 48 in FIGS. lhand 1i. This device includes a shift motor 50, which may be y'similar tothe motor 215 of FIG. 3, making a complete revolution in one minute whenonce energized. Coupled to the motor are fourteen cams 52A to I, Off,start, `fclock correction, and hold which close their associatedswitches-for corresponding fractions of the minute Acycle., For the: Ato I, start and Off cams, these times `are indicated A4in I"'I G`.Y2.lThe hold cam closes its switchfthrough .all but a fraction of the firstsecond of the oycle, the "clock correction cam closes its switch for aselected short portion of the cycle for energization of the clockcorrection relay in FIG. 1b, so that correction impulses of oppositepolarity may be sent to the program Ainstruments through the polarityrelay assembly 18, in .accordance withdetails of the construction of theprogram instruments not material to an understanding of the Closure ofthe cycling device cam switches A to .T start and OE, serves to extend,to a con ductor 54 at corresponding phases of the cycle,vpower lfromthose? of thetwelve input conductors l61 to 72 to those switches whichare m any minute cycle energized, in accordance with the make up of thesignal to bedef' veloped. Energization of this conductor 54 completesthe energizing circuit for the actuating coil.of a trans. mitter pulsingrelay 56. Closure of the singlenorm'ally open contact on this relaycompletes a circuit. from an energized conductor 58 through a conductor60 andthe contacts of the frequency selection relays 46, whose operationwill be explained presently, to one of the transmitter input conductors2, 4, 6 and 8.

Activation of appropriate ones of the input conductors 61 to 72 to thecam operated switches of the cycling device 48, and of a selected one ofthe frequency selection relays, is the consequence of energization, byzmeansxof the program instruments already described andloffjcertainauxiliarycomponents, of one of thirtytwoxgroup".'con ductors 101 to 132,of one of ve circuit conductors 141 to 145, of either an on conductor146 or of an off conductor 147, and of one of four .frequency selectingconductors 151 to 154.

The frequency selecting conductors lead directly from the frequencyselecting network of FIG. 1d, comprising motor driven contactsassociated with drums;28-F' and 28-F", to the actuating coils of therelays 46-11 to 46-'-f4.

The group, circuit, and On and Off conductors 101 to 132, 141 to 145 and146 and 147 on the other hand lead toa plurality of cycling devicevinput line selecting units, one of which comprises the whole of FIGS.v1g,. 1h,4 1i, and lj with the exception of the cycling device and trans=mitter pulsing relay already mentioned.` The On, Off, and circuitconductors 146, 147 and 141 to 145 lead into each one of these inputline selecting units. In the embodiment illustrated each unit isequipped toy pre,- pare signals of only two different combinations ofthe group selection pulses A to E. Each unit therefore re; ceives asinput only two of the group conductors 101 to 132.

Power for the complete apparatus of FIG. l, for example at volts, 60cycles, single phase, is suppliedto two input conductors 74 and 76 (FIG.la). Conductor. 74 may conveniently be assumed to be grounded. The mainon off power switch is shown at 78.` Whenl closed, it energizes aconductor 80, one of whose extensions 82 applies power to one of thecontacts of switches 38 on the scheduling drums, 28-I to 28IV, and ontheOn and Off drums 28On and 280ff of the third program instrument.

Let it be assumed that a signal Start A B C'D E F is to be generated onf1 carrier frequency at 14:52 hours on Tuesday. This means that each ofthe drums 281A to 28-F in FIG. 1c will have a schedule pinthe 892nd pinhole thereof, that the On drum of FIG. 1e will have a pin in that holelikewise, that the Off drum will not, and that of the one or moreschedule drums I-to IV of FIG. 1e which may have a pin in that hole oneand only one, drum I, say, will be effectively in circuit by thepresence in operative position of a tooth onits calendar cam 42 for thefourth twelve hour period of the week, assumed to begin at Sundaymidnight. It also means, in view of the make-up of the network v178 offrequency conductor selecting contacts operated by drums 28-F' and 28-F,that neither of those drums will havea sched ule pin in the 892nd holethereof. A .1'

Closure of the switch 38 on drum I at 14:52 h'ours on Tuesday willextend power from conductor 82 to a conductor 84, through the left-mostdeck of a ganged manual schedule selection switch 86 to a conductor-88and thence, through the closed calendar switch 40 to a conductor 90.

Associated with each of the program instrument drums', except the On andOi'drums 28-On and 28-O`f, is a shift motor 92 of l r.p.m. output shaftspeed, like the motor 215 of FIG. 3. Each of these motors is coupled atunity speed ratio to a cam 94 operating one or more switches shown inthe' figures? aligned -in'a*ve`rtical'row directly above such cam. A.rst normally :open switch vgrounded terminal of the associated motor92. On each of the 28-On and 28-Off drums a conductor 91 leads from theside of switch 38 opposite the energized conductor 82 directly to theungrounded terminal of the associated shift motor 92. Similarly on eachof drums v28-A to 28-1, 28-F and 28- a conductor 91 leads from thecontact of the switch 38 of that drum opposite a conductor 170, to bementioned presently, to 'the -un- :grounded terminal of the associatedshift motor 92.

The other switch contacts operated by the cams 94 of scheduling drums28-1 to 28-IV, shown within a rdash line box 160` are arranged andinterconnected to insure that power is extended from an extension 162 ofconductor 80 to a conductor 1-64 if and only if one and only one of thedrums 28-I to 28-IV having a schedule pin for the instantaneous minuteinterval is calendared in, i.e. yrendered operative during theinstantaneous twelve hour period by its cam 42. This prevents thegeneration of signals from conflicting schedules 'but requires that onebe calendared in and have a schedule pin for the minute in question.

A set of switch contacts shown at the dash line box 166 which areoperated by the cams 94 of the motors 92-On and 92-Oi are likewisearranged and interconnected to insure completion of a circuit fromconductor 164 to a conductor 168 if and only if one and only one ofthose motors is energized, i.e. if and only if one and only one of drums28-0n and -28-Of has closed its Vswitch 38.

Since the actual response of the load devices such as lamp 224 in FIG. 4occurs at or about the starting time of the Off `pulse of FIG. 2,somewhat in advance of the end of the minute interval shown in thatfigure, and since it is desired to make possi-ble such response at thebeginning of each minute interval of true time, the program instrumentsare operated a few seconds in advance of true time and the selection,i.e. encrgiz'ation, of a combination of group, circuit and frequencyconductors for activation of a cycling device input line selecting unitis varranged to occur with a delay suitable to cause the start vpulse ineach transmitted signal to begin a little Iater than zero seconds ofunit intervals of true time. In this Way the time of the Off pulse maybe made to coincide vwith the beginning of each minute of true This isaccomplished Iby the interposition of a time delay between theenerlgization of conductor 168, representative of a correct schedulingat drums 28-1 to 28-IV and of correct arrangement of the drums 28-On and`28-Oi, and the energization of conductors 170 and 172. Conductor 170feeds the input contacts of switches 38 on drums 28A to 28-1, 28-F and28F". Conductor 172 feeds the group selection network 174 of camoperated switches associated with drums 28-A to 28-F, lthe circuitselection network 176 of cam operated switches associated with drums28-F to Z8-I, and the frequency selection network 178 of cam operatedswitches associated with drums 28-F and 28-F.

To this end conductor 168, after passing through a normally closed camoperated 'switch on each of the manual on and manual off 1 r.p.m. shiftmotors 180 and 182 presently to be described, connects with theungrounded terminal of a start l r.p.m. shift motor 184. This motordrives a cam 186 which for substantially one minute closes a holdcontact for motor 184 to conductor 98 and which opens contacts in serieswith conductors 188 and 190 provided for energization of motors 180 and182 by operation in one or the other direction of -a manual switch 191(Fig. 1L) when manual control of the cy- 10 cling device is undertaken.Coupled to motor A1(8"4is a second cam 192 which effects, with a tensecond delay, for example, a short closing (e.g. tive seconds) of afurther contact between yan extension 194 of energized conductor and afurther conductor 196.

With ten second delay therefore, after the beginning of the vminutecycle of the program instruments, power is applied to a time delay 1r.p.m. shift motor 198 whose first cam 250 establishes a one minuteholding vcircuit therefor to conductor 98 and opens yfor one minutecontacts in series with the continuations 188:1 and 190a of conductors188 and 190 through the switch contacts Iof motor 184.

A second cam 252 on motor 198 closes, without delay but for an intervalof a tew seconds only, a contact bctween energized conductor 98 and aconductor 254 which leads, through a normally closed cam operated switchcontact on each of rnotors 180 and 182, .to conductors 17 0 and 172.

With ten second delay therefore over the start of the minute cycle ofthe program instruments, power is made available at the switches 38 ofthe pulse and frequency selection program drums 28-A to 28-J, 28-F and28-F. Those of these drums having scheduling pins under their sensingfingers accordingly have their switches 38 closed, and the l r.p.m.shift motors 92 associated with those drums are accordingly energized.One minute holding circuitstherefor are at once established to conductorat the normally open cam-operated switch contacts immediately above thecams 94 of those motors while the other cam-operated switch contacts,for all of the drums 28-A to 28-1 28-F and 28- in the networks 174, 176and 178 effect energization of a selected one of the group conductors101 to 132, a selected one of the circuit conductors 141 to 145, and aselected one of the frequency selecting conductors 151 to 154.

In the example which has been assumed, of a signal A B C D E F on flfrequency at 14:52 hours on Tuesday, it may be seen from FIGS. lc and ldthat it will be conductors 101, 141 and 151 which will be energized. Theconvention for normally open and normally closed relay contacts (whethercam or solenoid driven) followed throughout the drawings is indicatedyby the legends n.o. for normally open and n.c. for normally closedapplied to the uppermost contacts on cam 94 of the shift motor 92associated with drum 28-A -in FIG. 1c. With this observation, a detaileddescription of the conductors and contacts in the networks such as 160,174, 176, 178 and the like is believed to be unnecessary. Normally openof course means open for the de-energized state of the shift motor towhose cam or cams the contact Yin quetion belongs, if the contact is camoperated, and, in solenoid operated relays, normally open of coursemeans open for the de-energizcd state of the actuating coil of suchrelay.

With conductor 101 energized the appropriate one of the cycling deviceinput line activating units has been selected, namely that which isshown in FIGS. lg, lh, 1i and 1i within dash line box 256 sinceconductor 101, of the pulse group A B C D E, leads at an extension 101athereof into that box.

With conductor 141 energized, the extension 141a thereof which leadsinto box 256 is also energized, and with conductor 151 energized, theactuating coil of the frequency selecting relay 46f1 is energized also.In view of the coded make-up ot the unit 256, presently to be described,energization of its input conductor 101a will produce generation in thetransmitter 1 of the corresponding ocmbination A B C D E of groupselection pulses. With conductor 141a energized, unit 256 will inaddition cause the transmitter, if it is functioning properly, totransmit the circuit identification pulse F.

The on as distinguished from off nature of the signal to be developed(i.e. the absence or presence of -an Off pulse therein) was determinedby the presence of

